Heretofore, as a kind of stencil printing, screen printing that forces a printing substance through open mesh apertures perforated with a desired image pattern onto an object to be printed, thus transferring the printing substance to the object, is known. For this screen printing, making a printing screen is performed as follows. A “stretched screen master” is prepared by stretching a screen master on a frame in a tense state with predetermined tensile force. The screen master is made by bonding a thermally fusible film (hereinafter, simply referred to as a “film”) which is made of a thermoplastic resin such as polyester film or polyvinyl chloride film to a mesh fabric which is a mesh of plain fabrics made of weft and warp fibers of, e.g., silk, synthetic resin (such as nylon and tetrone), stainless, etc. with an adhesive agent. A film surface of the stretched screen master thus prepared is thermally perforated by a thermal head which is a perforation unit and a desired perforated image is created. As an apparatus for making such a printing screen, apparatuses which are disclosed in, e.g., Japanese Unexamined Patent Application Publications No. Hei 6-270379 and No. Hei 9-70940 are publicly known.
In an apparatus of Japanese Unexamined Patent Application Publication No. Hei 6-270379, the master part of a stretched screen master is mounted on a flat plate platen which is fit for the size of the stretched screen master and making a printing screen is performed in a state in which the screen has been brought in close contact with the thermal head. In an apparatus of Japanese Unexamined Patent Application Publication No. Hei 9-70940, a screen master is held between a long thermal head which contacts the entire width of the mesh fabric of the screen master and a platen which is provided to face the thermal head and making a printing screen is performed in a state in which the master has been brought in close contact with the thermal head.